Soyrisk - a Decision Support Tool for Managing Risk and Profitability Using Simulated Soybean Yields for the Midsouth.

Soybean (Glycine max (L.) Merr.) planting date and maturity group (MG) decisions can be used to manage production risk and profitability. SOYRISK is a spreadsheet based tool that can assist producers in maximizing revenue expectations while minimizing risk for irrigated soybean production in the US Midsouth. A 3-yr planting date study across nine locations that comprised a total of 91 site x year x planting date combinations and MG 3 to 6 cultivars was used to calibrate and validate DSSAT-CROPGRO in the prediction of developmental stages, yield and seed oil and protein concentration. Simulations with calibrated cultivar coefficients by MG demonstrated an overall robust model performance in capturing MG x environment x management interactions. Thereafter, a simulated database was generated that included 13 locations, 30-yr of historical weather data, eight cultivars from early MG 3 to late MG 6, and two representative soils (silt loam and clay) (total of 87,360 scenarios). Revenue expectations for each scenario were adjusted by harvest date, oil and meal premiums or discounts, and irrigation requirements. Production costs are user specified and are constant across MGs and planting dates. Using portfolio theory, the tool maximizes profitability while minimizing risk. Users input a location-specific baseline MG x planting date scenario in SOYRISK and the tool identifies management alternatives: i) with greater profitability at equal or lesser risk; ii) that provide maximum profit per unit of risk; and iii) that meet a user-specified irrigation constraint. These alternatives are calculated for an available planting window from March to June that can be modified to a shorter planting season by the user. Diversified management recommendations are provided for up to nine MG x planting combinations. The potential of this tool for production risk and profitability management is presented with an example.